1. Field of the Invention
The present invention relates to a display device such as a liquid crystal projector.
2. Description of the Prior Art
Optical components such as a liquid crystal panel, a light source lamp for backlight arranged on a rear surface of the liquid crystal panel, and a polarizing plate are provided inside a casing of a liquid crystal projector. A cooling suction fan for preventing the optical components from being degraded due to the rise in temperature by turning the light source lamp for backlight on is provided inside the casing of the liquid crystal projector. Further, an air filter is provided in order for dust and dirt not to enter the casing in case of suction by the cooling suction fan.
When the liquid crystal projector is used for a long time period in an environment where air is dirty, the air filter is clogged, so that the capability of suction by the cooling suction fan is lowered. Accordingly, the temperature rises, thereby degrading the optical components.